In the past, various different types of tube fittings were arranged in an auto-ignition zone of a gas turbine engine for aircraft to interconnect tubing or other components conveying a flammable fluid adapted for combustion to drive the gas turbine engine. It is believed that the potential existed for uncontrolled leakage of the flammable fluid from such past tube fittings into the auto-ignition zone of the gas turbine engine which may have caused a fire or loss of power therein resulting in an undesirable In Flight Shutdown (IFSD) of the gas turbine engine.
At least one of the previous schemes for resolving the aforementioned uncontrolled leakage flow of flammable fluid from the past tube fittings was to contain such leakage flow and convey it away from the auto-ignition zone of the gas turbine engine. The aforementioned previous scheme utilized shrouds in association with the past tube fittings to collect the leakage flow of the flammable fluid thereby to isolate such leakage flow from the auto-ignition zone of the gas turbine engine, and drain tubes connected with the shrouds conveyed such leakage flow away from the auto-ignition zone into a non-ignition zone of the gas turbine engine. Thus, the conveyance of the leakage flow of flammable fluid away from the auto-ignition zone obviated the combustion therein of such leakage flow of flammable fluid.
While the above discussed past scheme undoubtedly had many salient features, some of the disadvantageous or undesirable features thereof are believed to be that the shrouds and drain tubes not only added to the complexity of the gas turbine engine construction thereby to increase maintenance time but also added to the weight of the gas turbine engine. At least another disadvantageous feature of the above discussed past scheme is believed to be that the shrouds and drain lines did not limit the rate of the leakage flow of flammable fluid from the past tube fittings, and such leakage flow may have become excessive.